Washing Machine Comprising a Laundry Tub

ABSTRACT

A laundry tub pertaining to a washing machine, said laundry tub comprising a laundry driving system that can be driven from outside the tub by means of a disk-shaped drive element. At least one of the facing surfaces of the tub and the drive element has a surface structure. One such laundry tub presents the risk that the surface structures act like an oscillator in the washing machine, causing disturbing noises during the spinning program. According to the invention, said risk can be at least reduced by providing one of the two surfaces with a cover homogenizing the surface structure.

The invention relates to a washing machine comprising a laundry tub anda laundry driving system located therein, that can be driven fromoutside the tub by means of a disk-shaped drive element, wherein atleast one of the facing surfaces of the tub and the drive element has asurface structure.

Such a washing machine is known from EP 0 152 745 B1. Used therein as adisk-shaped drive element for a laundry drum is a pulley having a hub atthe centre and a rim on the outside, and a transmission belt whichobtains its drive energy from a drum drive motor runs on the outersurface thereof. The hub and the rim of the pulley are interconnected byspokes; at least three wider or five narrower spokes are provided.

In addition, the washing machine contains a soap solution container as acontainer for the laundry. A laundry drum is mounted horizontally androtatably in the soap solution container. This drum is drive by thepulley by means of a shaft. The rear wall of the soap solution containeris folded in a meander shape, whereby spoke-shaped structures are formedwhich help to stabilise the rear wall. In other known washing machinesin which the soap solution container is made of sheet steel, the rearwall structure is formed by a spider of cast steel which forms a surfacestructuring similar to that in the washing machine according to EP 0 152745 B1.

In washing machines whose laundry drums are driven at very high speedsduring the spinning process, e.g. at speeds beyond 1600 rpm, thestructures of the facing surfaces of the driving disk and the rear wallof the container which brush past one another, together with the airlocated therebetween, produce an organ-like noise which can be verydisturbing.

It is the object of the invention to construct washing machines of thetype specified initially so that as far as possible these perturbingnoises cannot be produced.

This object is solved according to the invention by the characterisingpart of claim 1 in a manner such that at least one of the two faces isprovided with a cover which homogenises the surface structure. As aresult, the structures are decoupled from one another so that suchperturbing noise can no longer occur.

According to a particularly advantageous embodiment of the invention, ina washing machine comprising a pulley serving as a drive elementcomprising a rim which guides the belt and a number of spokes whichconnect a hub to the rim, the spokes are provided with a flat cover. Asa result, the structuring of the surface facing the soap solutioncontainer, provided by the spokes, is covered with a uniform face whichno longer causes any air vibrations during rotation of the pulley whichtogether with the structure of the soap solution container rear wall,could build up to an audible air sound vibration.

A similar effect would be obtained by another advantageous embodiment ofthe invention in a washing machine comprising a soap solution containermade of plastic which serves as the tub, whose base facing the driveelement is formed as a surface-structured face such that spoke-likereinforcements of the base are obtained from a meander-shaped folding ofthe base wall if, in this washing machine, the reinforcements areprovided with a flat cover.

In all these cases, the cover can advantageously consist of a film, inparticular a highly flexible plastic film.

In this case, the film can advantageously fixed by means of mechanicalmeans to the drive element or the base. For example, a clamping ring forthe film which can be affixed to the circumference by means of detentmechanisms can be provided. This would have the advantage that the filmcan easily be exchanged.

However, the film can also be stuck to the furthest-protrudingstructural surfaces, e.g. to the spokes of the pulley or to thereinforcements of the container rear wall, with the respectivestructured surface.

The invention is explained hereinafter with reference to an exemplaryembodiment shown in the drawings. In the figures:

FIG. 1 is a perspective view of the back of a washing machinesoap-solution container with a pulley without using the measureaccording to the invention and

FIG. 2 is a partial section vertically through the rear part of a soapsolution container according to FIG. 1 using the measure according tothe invention.

The exemplary embodiment shown relates to a washing machine comprising aplastic soap-solution container or tub 1 for receiving a horizontallymounted laundry drum 2 (FIG. 2). The rear wall 3 of the soap solutioncontainer has a meander-shaped structure so that spoke-likereinforcements 4 are obtained, leaving corresponding cavities 5 freebetween them.

Located at a flat distance from the rear wall 3 (from thefurthest-projecting faces of the reinforcements 4) is a pulley 6 whichis connected rotationally fixedly to a star-shaped support 8 of thelaundry drum 2 by means of a shaft 7. For this purpose the shaft 7 ismounted horizontally rotatably in the hub 9 of the soap-solution rearwall 3.

The pulley 6 has a hub 10 which is connected rotationally fixedly to theshaft 7. The hub 10 is connected to the rim 11 of the pulley 6 by meansof five spokes 12 which expose large intermediate spaces therebetween inthe example shown. When the pulley 6 turns, the air masses entrained bythe spokes impinge upon the structures of the soap solution containerrear wall 3 and cause vibrations which cause an organ-like sound whenrotating rapidly which can be disturbing. In addition, these vibrationscause alternating micro-loads on the structural elements concerned to alarge extent which can develop into an overall harmful stress on thestructural elements.

In order to avoid disturbing noises and permanent stress on thestructural elements, according to the exemplary embodiment of theinvention shown here a flat cover of the respective structures isattached at least to one of the facing surfaces of the tub 1 and thedrive element 6. For this purpose, a thin e.g. film-like cover 13 isapplied to the side of the pulley 6 facing the soap solution container1. This cover will possibly be sufficient to avoid the feareddisturbances. Instead of this cover, a single cover 14 of the rear wall3 of the soap solution container 1 may well be sufficient. However, ifone of the covers is not sufficient, both covers 13 and 14 can also beused so that there are no discontinuities of the surfaces brushed by theentrained air.

The covers can be attached in various ways. The simplest method ofattachment can be achieved by gluing. However, purely mechanical typesof application (screwing, detect mechanisms, plugging) are also feasiblewhereby, among other things, it is possible to exchange the covers.

1-8. (canceled)
 9. A washing machine comprising a laundry tub having arear wall with a first facing surface and a laundry driving systemlocated therein, that can be driven from outside the tub by adisk-shaped drive element having a second facing surface, the first andsecond facing surfaces facing one another, wherein at least one of thefirst and second facing surfaces has a surface structure and a coverdisposed over the surface structure homogenizing the surface structureand providing a substantially flat disc-shaped surface.
 10. The washingmachine according to claim 9, further comprising a pulley serving as adrive element comprising a rim which guides the belt and a number ofspokes which connect a hub to the rim, wherein the spokes are providedwith a cover over the second facing surface having a substantially flatdisc-shaped surface.
 11. The washing machine according to claim 9,wherein the rear wall of the tub includes spoke-like reinforcementsobtained from a meander-shaped folding of the base wall, a substantiallyflat disc-shaped cover being disposed over the spoke-likereinforcements.
 12. The washing machine according to claim 9, whereinthe cover includes a film.
 13. The washing machine according to claim12, wherein the film includes a highly flexible plastic film.
 14. Thewashing machine according to claim 12, wherein the film is affixed bymeans of mechanical means to at least one of the drive element and tothe rear wall.
 15. The washing machine according to claim 11, furthercomprising a pulley serving as a drive element comprising a rim whichguides the belt and a number of spokes which connect a hub to the rim,wherein the spokes are provided with a cover over the second facingsurface having a substantially flat disc-shaped surface, the coverincludes a film at least partially glued to at least one of the driveelement and to the rear wall.
 16. The washing machine according to claim15, wherein the film is glued to at least one of the spokes of the driveelement and the spoke-like reinforcements of the tub.
 17. A washingmachine comprising: a tub including a rear wall having a hub; a drumdisposed within the tub and mounted for rotation with respect to thetub; a pulley disposed adjacent the rear wall and driving the drum andhaving a pulley hub, a rim, and multiple spokes extending between thepulley hub and rim; a cover mounted on the pulley covering the spokesand providing a substantially flat disc-shaped surface facing the rearwall.
 18. The washing machine according to claim 17, further comprisinga shaft extending through the hub of the tub and connecting the pulleyand the drum to one another, the drum and the shaft rotating in responseto rotation of the pulley;
 19. The washing machine according to claim17, wherein the cover includes a flexible plastic film material.
 20. Thewashing machine according to claim 17, wherein the cover is mounted onthe pulley with an adhesive.
 21. The washing machine according to claim17, wherein the cover is mounted on the pulley with a mechanicalfastener.
 22. The washing machine according to claim 17, wherein therear wall of the tub includes multiple spoke-like reinforcementsextending radially outwardly from the hub and cavities formed betweenthe spoke-like reinforcements, the washing machine further comprising asecond cover mounted on the tub covering the spoke-like reinforcementsof the rear wall and providing a substantially flat disc-shaped surfacefacing the pulley.
 23. A washing machine comprising: a tub including arear wall having a hub, multiple spoke-like reinforcements extendingradially outwardly from the hub, and cavities formed between thespoke-like reinforcements; a drum disposed within the tub and mountedfor rotation with respect to the tub; a pulley disposed adjacent therear wall and driving the drum; a cover mounted on the tub covering thespoke-like reinforcements of the rear wall and providing a substantiallyflat disc-shaped surface facing the pulley.
 24. The washing machineaccording to claim 23, further comprising a shaft extending through thehub of the tub and connecting the pulley and the drum to one another,the drum and the shaft rotating in response to rotation of the pulley;25. The washing machine according to claim 23, wherein the coverincludes a flexible plastic film material.
 26. The washing machineaccording to claim 23, wherein the cover is mounted on the rear wallwith an adhesive.
 27. The washing machine according to claim 23, whereinthe cover is mounted on the rear wall with a mechanical fastener. 28.The washing machine according to claim 23, wherein the pulley includes apulley hub, a rim, and multiple spokes extending between the pulley huband rim, the washing machine further comprising a second cover mountedon the pulley covering the spokes and providing a substantially flatdisc-shaped surface facing the rear wall, the cover and second coverbeing formed from a flexible plastic film material.